Optimization of bacillus sphaericus induced calcite precipitation in ground improvement process.

In recent two decade, researchers are working on new emerging area Bio-gio engineering. Microbialy Induced Carbonic Precipitation method is getting popularity because of its sustainability, feasibility, eco friendly nature and economy as compared to the other mechanical and chemical ground improvement techniques. This research is focused on optimal use of two important input variables, retention time and chemical concentration to induce CaCO3 precipitation in open environments using Bacillus Sphaericus. Most of the studies on bio mineralization are done with microbe Sporosarcina pasteurii,we have used microbe Bacillus Sphaericus for optimisation in Indian context. To optimize the retention time and chemical concentrations,different combinations of injections and chemical concentrations were tried and precipitated in porous sand media to achieve the required density and to access the optimize pumping rate for bio mineralization. Results showed that,the input rate of 0.1Molar,0.25Molar and 0.5Molar liquid media input can be optimized to 0.04M/L/H to get higher and homogeneous precipitaton. The concentration of liquid solution in the input could be as high as 1 Molar and as low as required,depending upon number of injections. The performance efficiency was homogeneous through different cementation stages upto precipitation value of 0.03gm/gm of sand (i.e.3%). The efficiency was decreased as moving towards the higher molar solution. The optimized values for experimental factors were calculated and discussed. [ABSTRACT FROM AUTHOR]